a.Two forces 3 N and 4 N act at
right angles to each other, their resultant force will be _________

b.The apex angle of a cone of
friction is 45°. The coefficient friction will be __________

c.______ is the ration of load
lifted to the effort applied.

d.The product of a force and the
perpendicular distance of the line of action of the force form a point is known
a ____ of the force abut that point.

e.If a body is in equilibrium and
is acted upon by two forces, then they must be equal, opposite and _____.

State
true of false

I.All such forces whose lines of
action are lying in one plane are called coplanar forces.

II.An ideal machine is one in
which efficiency = 100%

III.The C.G. of a hemisphere lies
at a distance of 3r/8 from its base along vertical radius ‘r;

IV.The force of friction developed
between the surface of contact of two bodies in the position of rest, is static
friction.

V.Rolling friction is more than
sliding friction.

Section –B

Note
: Attempt any five question

2.

a.What do you mean by rigid body?

b.Write briefly about principle
of transmissibility of forces

c.State and prove lami’s theorem.

d.Derive the condition for
irreversibility of a machine.

e.Differentiate between static
friction and dynamic friction.

f.What is centre gravity?

g.What are conditions of
equilibrium of a body?

Section
–C

Note
: Attempt any three questions

3.Two forces 2P & P
respectively act an a particle. If the first force is doubled and second force
increased by 120 N, the direction of resultant remains unchanged. Determine
value of P.

4.A body consists of solid
hemisphere of radius 4 cm and a right circular solid cone of height 12 cm. The
hemisphere and cone have a common base and are made of the same material.

5.A uniform ladder of weight 250
N and length 5 m is places against a vertical wall in a position where its
inclination of the vertical is 30°. A man weighting 800 N climbs the
ladder. At what position will be induced slipping? The coefficient of friction
of both the surfaces of contact of the ladder 10.2

6.A load of 2.5 KN is to be lifted by a screw
jack having threads of 10 mm pitch. The efficiency of the jack at this load is
50%. Determine effort applied at the end of a handle of 50 cm length.